Clutch tap and die holder



Nov. 21, 1944. J. F. ALLEN 2,363,379

CLUTCH TAP AND DIE HOLDER Filed .my 14, 194s H n llllll 5 EU? iQ Trop/wry: l

right hand opening 2|, while in Fig. 6 when the tap and die holder is used for cutting left hand threads the plunger 23 is mounted inv the left hand opening 2|. The plunger 23 is springpressed by means of a coil spring 24 which abuts the outer end of the plunger and the inner end of a screw 25 secured in the threaded counterbore 22. The inner end of the plunger 23 engages the side of the pendulum memberA I8 and rocks said pendulum in a clockwise direction as viewed in Fig. 3 to hold the opposite side of the pendulum in contact with the left hand side wall of the slot I1.

The tap or die carrying unitY II comprises a portion extending outwardly of the bodynlo and provided with a tool socket 26 and in which socket the tool, such as a tap orvdie, can be secured by means of clamping screws or other suitable well known means. The tap or die carry-A ing unit |I hasl a portion 21 which extends into the chamber I3 and rotatably interfits the opening inthe body I0 which communicates with said chamber. A shaft 28 extends from the portion 21 and'passes'through the bore I6 of the shank I2 and rotatably interflts the reduced bearing portion of said bore. The outer end of the shaft 28 is provided with a shouldered washer 29 held in position by a screw as is well understood in the art. The tap and die carrying `unit II has a limited relative endwise move- 'ment in the body I0 and the limits of such movement are defined by the engagement of the inner end of the portion 21 of the unit II with the end wall I4 ofthe chamber I3 as shown in Fig. 1 and by theV engagement of the shouldered washer 29 with ythe shoulder formed by the reduced bearing portion of the bore IIS` as shown in Fig. 2.

The portion 21 of the tap or die carrying unit is provided with a diametrically extending opening 30 therethrough and in which opening there is slidably mounted a clutch member 3|. The lower end of the clutch member 3|, as viewed in the drawing, is provided with a transverse slot l32 through which extends a pin 33 carried by the portion 21 and extending transversely of the opening 30. The pin 33 when positioned in the 'slot 32 prevents the clutch member from turning in ther opening 30 but allows sliding movement thereof in said opening. The clutch member 3| is provided with a centrally located recess extending longitudinally of the clutch member from the inner end thereof and in which recess a coil spring 34 is mounted and abuts the end of the recess and a shouldered washer 35 which washer, in turn, contacts the pin 33. The spring 34 constantly urges the clutch member 3| in a radially outward direction-in the opening 30 of the portion 21. of the tap and die carrying unit I I. The outer end of the clutch member 3| is provided on opposite sides with cutaway portions 36 and 31 and which portions form contact surfaces for cooperation with the contact surfaces 20 of the pendulum member I8. The outer end of the clutch member 3| at right angles to the cutaway portions 36, 31 has beveled surfaces 38 on each side and one or the other beveled surface coopcrates with the conical end wall I5 of the cham- Iber I3 for a purpose later to be explained and depending upon the hand of the threads being l cut. The extreme outer end of the clutch member 3| iscurved to provide a camming surface 39 so shaped that the cutaway portion 31 is longer than the cutaway portion 36,` as clearly indicated -in Fig. 3 and for "a purpose llater tobepointed out. I

The normal relationship of the body unit ID and the tap or die carrying unit II and the parts associated therewith is indicated in Figs. 1 and 3. It being assumed that the shank I2 is secured in the tool holding member of the slide of a machine tool and that a tap or die is mounted in the socket 26 of the unit II the operator will cause the slide to move to bring the tap or die into engagement with the work and will continue such movement while the tap or die is cutting threads in or on the work. During the referred to movement of the slide the inner end of the portion 21 of the unit II of the clutch tap and die holder is in contact with the end wall I4 of the chamber I3 of the body unit I0 as shown in Fig. 1 and the contact surface provided by the cutaway portion 36 of the clutch member 3| is in 'engagement with the left hand contact surface 20 of the pendulum member I8 and said latter member has been rocked in an anti-clockwise direction `against the right hand side wall of the slot I1 to move the plunger 23 and compress the spring 24, At this time and during the threading operation the units Il) and |I`of the holder have no relative rotative movement as they are interconnected by the engagement of the pendulum and clutch member. Near the end of the vthreading operation the movement of the slide is terminated, but due to the engagement of the tap or die with the rotating work piece the unit I I has endwise movement imparted thereto toward the left and relative to the unit I6. This endwise movement results in the clutch member 3| being cammed radially inwardly against the action of the spring 34 by the engagement of the beveled surface 38 and the conical end wall I5 of the chamber I3. The inward movement of the clutch member 3| continues until the contact surface provided by the cutaway portion 3s is disengaged from the contact surface 20 of the pendulum` member I8 as shown in Fig. 4,A and at this time the unit II is free to rotate with the work and relative to the unit I0. As the unit II rotates relative to the unit I0 the curved end 39 of the clutch member 3| engages the inner end of the pendulum member I8 and the clutch member is depressed slightly farther as it passes the pendulum member I8 during each rotation of the unit II. As soon as the clutch member 3| has passed the pendulum member I8 the spring pressed plunger 23 rocks the pendulum member I8 in a clockwise direction asviewed in the drawing until it engages the opposite side wall of the slot I1. As the rotation continues and the clutch member 3| again passes by the pendulum member IB it will be noted that the curved surface 39 on thev end of the clutch member contacts the inner end of the pendulum I8 while the pendulum is in its left hand rocked position as just explained. This engagement of the curved end of the clutch member 3| with the inner end of the pendulum member I8 momentarily rocks the pendulum toward the right and against the action of the plunger 23 and momentarily slightly depresses the clutch member 3| as it passes by the pendulum. This'continues each time the clutch member passes the pendulum during the relative rotation between the body unit I0 and the unit I I.

Itv will be noted that during said relative rotation between the units I0 and II and the passing of the pendulum member I8 by the clutch member 3| the knife edges at the ends of the contact surfaces of said lmembers do not come into contact with each other and therefore will vfrio"verricht*just explained? Wlenthe? operatbr l -f-'I Willftu'rrrwith1 thefwork pice/inthe reverse direction'since it is-'thradedly connected there- A'vvi'th'y throu'ghgthe tap or die; This reverse'rotae v-t'i'n'l ofy the -unit I licontinuesuntil'thelarger coni 'tact surfaceformedf byv the cutaway portion' 311 vof theclutch` member 3| 'engagestheright-'hand` contact surface 20 of the pendulum* member i8 A'as shown inlFi'g. 5i soon asl thisi engagement "takes plato-eine unit-*H is held-against rotation :inr thev reverse direction' relativeA tothe unit lll -and consequently the tap or'A die carried by the uniti irwill back offl the-threadv cut in"y or'on the Work piece'. Simultaneously with" the backing off fofi the' tap or dieV the" operator willl causez 'the "slide to* move" rearwardly to' its originall position and'r the tapor' ldie' Willl be' withdrawnjf'rom" the workpiece; y v y Assuming that the operatormoves" theL yslide rearwardlytat the same rate'` as the tap or' die backs' off from the Work then' assoorr as the tap "or llisis .free of the work the units'v wand ffl and the" parts carried therebyj'will bfe rejfrfsitoredr to their normal relationship.' Tl'lisf'is .occasioned through the' action' ofthe springiffd ifforcing the' clutch member` 31' radially' outas previously explained.A

thel pendulumrmemlieri I 8' andA the 11 clutchl mem:- berlf are, lnterengagedf and the yclutch mem@- lierf holds 1 the pendulum; member: inA rocked posir tionagainst the left ahand side of tllezslotv H andfthe' plunger' 243'is' depressed against thefs'pring 2'4, asshoWndn. Fig. 6.V l

The manner in which the' partsfunctionwhen assembled for cutting left;` hand? threads is iden'- tical with the manner' in which they function when assembled for cutting' right hand. threads It willl be understood 'that When-they unitlfl is'rotating relative:y to the unit Illafter'the: parts have beenreleasedf said unit'. willf rotate in'. the opposite direction from the direction inrwhich iti-rotated whenl released: after cutting right hand threadsi f l' v From the foregoing description' it will have; been seen lthat the sharpr or knife edges at' the` outer ends of the cooperating"contacting surfacesf of the pendulum member I'8 andthe clutchmem.- ber 31- separate upon the" commencementfofthe relative rotation of the unit H2 after-the reo leasing of' the parts vand do not'comeintor con'- tvardly, wherefore' the'beveled'surface' 38` of the i clutch member will' ride onr the conical erid ,.'Wallfsurface I'5` and' effect endwise movement of the unit Il toward the right' and' relative'l'tfo ythe unit I until the parts are in theirnormal lations'hipga's'shown in Fig;` 1'.

, fr The" description o f thev clutchv tap andfjdi'efv holder previously set forth herein' in' detail rieferrd'to the assembly of the' parts in' connecnon' 4with the use of ,the holder forv cutting til-reads of a particular han@ namely,` right haria threads'. yIn Fig. 6 the 'parts of the clutch tap v jandj die holder are shown assembled fori the .o cutting of ythreads of the opposite hand", namely,` lleft hand' tlfireacls'.rv This latter' assemblyo 'the fv'partsj simply involves'l withdrawing the unil-2j.,Y t from the" unitv lu Vby removingv the sho'uldjered"y lglva'sher 2S)v and'itsret'ainingscrew an'd then". slifding the unit' ll l1 out of' tlieunlt In; it being under- L stood that during' thisV sliding movement ofthe li'nlt yl I'the clutch member 3'l iS depresSedi'Sfufv1flciently't'o allow the unit H to' pull'throughj the 'Opening' of the unit |01 When the unit il" has `been removed suficiently fromthe unitj'llly the n kclutch m'eyrr'iberr 3l is disengaged from 'theipin `33 'by the spring 34 andr can then beiAv given aj .half

tot reverse thel relative positions of thec'onll'tact'surfaces formed'by the'cutaway portions 136v and 3l. l The unit Il can then bereinserted in the` unit IO by' depressing the clutchy member suncien'tly'to pass through the opening' inil the it`r i D and when the unit I I has been positioned ,infthe unit Il) in'its normal relationship: 4the lshouldered"Washer 29 an'd'itsv retaining screw'are "again` secured rto 4th'eend of the shaft 28j. yaddition the plunger Meis-(moved from `tliefrig'ht p .t

han'dop'ening Z'Iin thejunit I0, as viewed inthe y drawing; and mounted `inr vthe left :hand opening p "2l as i's also *the* springr 24. and its retaining l screw In other Words, the' p1unger`23 will tact during the further relative rotation-oi the unit Il and until the partsof the holder-arenile"- stored to their vnormal relationship.y Thisis-y due to the rocking movement of the pendulum' member under the'V actionV of the plunger 23 andfWl-li'ch movement places the knife edge of the pendulum member out of thepath of the 'knife'edgei of the `clutch member. i

The separation of the knife edges of the pendulum member and the clutch member solthat they do" not contact during the idle relative rotation of the' unit H eliminates damagey to= said knife edges and thus the accuracy of the clutchtap and kdie holderis retained throughout itsv life. It Will also be recalled that the pendulum memberl l8 has' four symmetrical contacting surfaces and knife edges' and canI be reversed sol as to utilize all of these' surfaces and edges and ythis feature is a lfurther assurance as to the Iong life and functional accuracy of the^r holder.

{now contact" with vthe left hand side of v 'the 'p pendulum member i8, as viewed inFig. 6|,jin-

[stead of withthe-riglit lhaini side ofthe penduf 'l'u'm" member las shown in'. the preceding'views.

'Whenjthe parts of the holder areza'rrange'd for 'thecuttingj of left' handv threads andA Aare injtheir 'nc'arnralAx relationship'the contacting "surfa'fces' of" It willl also `have been noted that' the clutch tap and die holder embodying' the present irl- 'vention is an improvement over the tap and die holders of the prior art due to its simplicity of design and elciency 'of operation and yits long Alife 4and accuracy lby vvirtue of the facility *for reversing the parts.

Y It' Will also have been notedthat the' holder can be readily adapted for' they cutting of either right ork left hand threads by ar fewfsimple changes in the assemblyof the parts; Although a preferred embodiment' of the invention has been illustrated and described herein it will be understood that theinvention is susceptible of various modifications and" adaptations Within the scope of the appended claimsi Having thus described my invention', I- claim: 1. Aftap and die holder comprising a unit having a cylindrical chamber therein' and a radially extending slot communicating withJ said vchami belga pendulum member mounted in said slot for movement Within the limits of the side- Walls thereof and extending into said chamber, another unit having a portion' extending into'A said chamber and rotatable and endwise movable therein, said portion being provided with a movo able clutch member normally cooperatively engaging said' pendulum member to interconnect said units against relative rotation', said clutch member when thus interengaged with said peni position, said first unit and said clutch member having cooperating portions acting upon relative -movement of said portion of said other unit within said chamber to move said clutch member to disengage it from said pendulum member to free said units for relative rotation, said rst named unit being provided with means acting upon said pendulum member to move the latter when thus disengaged from said clutch member to its other extreme position.

2. A tap and die holder comprising a pair of relatively rotatable and endwise movable units, one of said units being provided with an internal cylindrical chamber and a radially extending slot communicating therewith, said unit also being provided in the opposite sides of said slot with identical openings in one of which a springpressed plunger is mounted, a bearing element carried by said one unit and extending across said slot, a pendulum member rockably mounted in said slot on said element andrforcibly held by said spring-pressed plunger against one side or the other of said slot depending upon the loca- ,l tion of said plunger, the other of said units having a portion extending into said chamber and provided with a movable clutch member normally cooperating with said pendulum to hold the same against the side of the slot in which the springpressed plunger is located and against the action of said plunger-during the operation of the holder, said one unit and said clutch member having cooperating portions effective upon endwise movement of said units. to move said clutch member to disengage the same from said pendulum whereupon said spring-pressed plunger rocks the pendulum against the opposite wall of the slot.

3. A tap and die holder comprising a pair of relatively rotatable and endwise movable units having portions arranged one within the other, said portion of one of said units having an abutment member movable between predetermined limits and provided with an edge and said portion of the other of said units having a movable clutch member provided with an edge and normally cooperating with said abutment member to hold the latter at one limit of its movement and to interconnect said portions and said units against relative rotation, said portion oi said one unit and said clutch member having cooperating -camming surfaces acting upon relative endwise movement between said portions and units to dis engage said members to free said portions and said units for relative rotation, and means carried by said portion of said one unit and acting on said abutment member to move the same to, y.the other limit of its movement when thus dismovable clutch member provided with an edge and normally cooperating with said pendulum member to hold the latter at one limit of its movement and to interconnect said portions and said units against relative rotation, said portion of said one unit and said clutch member having cooperating camming surfaces acting upon relative` relatively rotatable and endwise movable units having portions arranged one within the other, the outer of said portions having an abutment member movable between predetermined limits and provided with an edge and the inner of said portions having a movable clutch member provided with an edge and normally 'cooperating With said abutment member to hold the latter at one limit of its movement and to interconnect said portions and said units against relative rotation, said outer portion and said clutch member having cooperating camming surfaces acting upon relative endwise movement between said portions and units to disengage said members to free said portions and said units for relative rotation, and means carried by said outer portion and `acting on said abutment member to move the same to the other limit of its movement when thus disengaged from said clutch member, at which time the edge of the abutment member lies outside of the path of relative rotation of the edge of the clutch member,

6. A tap and die holder comprising a [pair of relatively rotatable and endwise movable units having -portions arranged one within the other, the outer of said portions having a pendulum mem-ber substantially radially disposed therein and movable between, predetermined limits and provided with an edge, the inner of said po-rtions having a radially movable clutch member provided with an edge and normally cooperating with said pendulum member to hold the latterat one limit of its 4movement and to interconnect said portions and said` units against relative rotation, said outer portion and said clutch member having cooperating camming surfaces acting upon relative endwise movement between said portions and unitsI to disengage said members to free said portions and said units for relative rotation, and means carried by said outer portion and acting on said pendulum member to move the same to the other limit of its movement when thus disengaged from said clutch member at which time the edge of the pendulum lies outside of the path of relative rotation of the edge of the clutch memlber.

7. A tap and die holder comprising a pair of relatively rotatable and endwise movable units having :portions arranged one within the other, said portion of one of said units having a radial slot and apendulum member having movement in said slot limited by the side walls thereof, said pendulum member being provided with an edge, said portion of the other of said units. having a radially movable clutch member provided with an edge and normally cooperating with said pendulum member to hold the latter against one side wall of said slot and to interconnect said members and said units against relative rotation, said portion and said one unit and said clutch member having cooperating camming surfaces acting upon relative endwise movement between said ,portions and said units to disengage said meinbers to free said |portions and said units for relative rotation, and means carried by said portion of said one unit and acting onv said pendulum member to move the same against the other si'de wall of said slot when thus disengaged from said clutch member at which time the edge oiy the t pendulum member lies outside of the path of relal tive rotation of the edge of the clutch member.

8. A tap and die holder comprising a pair of relatively rotatable and endwise movable units,

v one of said units` having a substantially cylindrir cal .body provided with a cylindrical chamber therein with the wall of said body at diametriv cally opposite sides of said chamber of different thickness, the wall of said body of greater thick- .ness being provided with a slot communicating with said chamber and having a pendulum rockable therein and [provided with an edge located in said chamber, the other unit Yhaving a portion rotatable and endwise movable in saidjchamber and provided with a, movable clutch member having an edge and normally cooperating with said pendulum to hold the latter against one side wall of said slot and to interconnect-said body and said portion, wherefore said units are held lagainst relative rotation, said body and said clutch member having cooperating camming suri faces acting upon relative endwise movement between said units to disengage said pendulum and Y 9. A tap and die holder comprising a unit having a cylindrical chamber therein and a radially extending slot communicating with said chamber, `bearing means carried by said unit midway able clutch member having an edge and which clutch `member can be reversed rto position its edge at one side or the other of the clutch mem-A ber for either right or left hand threading operasaid clutch member to free said body and porr'tion and said units for relative rotation, and -means carried Iby said body and acting on said pendulum to move the same against the other side wall of said slot when said pendulum is disengaged from said clutch membervat which time the edge of the pendulum lies outside of the path of relative rotation of the edge of the clutch member.

tions, said clutch member normally cooperatively engaging said elongated member to interconnect said units against relative rotation and to hold Asaid elongated member against one side wall of said slot, said rst unit and said clutch member i -having cooperating portions acting upon relative endwise movement between said unitsl to move said clutch member to disengage it from said elongated member to free said units for relative rotation, and means carried by said first unit and acting on said elongated member to move the same against the other side wall of the slot When Jthus disengaged from said clutch member rat which time the edges of the elongated member lie outside of thek path of relative rotation of the edge of the clutch member.

JOSEPH F. ALLEN. 

